ORA-12324: cannot use the ROM: link type on a private database link
Cause : You can only specify the ROM: link type on a public, not a private, database link.
Action - How to fix it : DBA Scripts :: www.high-oracle.com/scripts
Determine if there is an existing public database link to the secondary database. If not, and if you wish to establish public access to the secondary database, create a public database link to the secondary database using the CREATE DATABASE LINK command.
Well, the reason for above error is that i have taken the above script from a 11g database and running it on 10g database. 11g has bring some changes in password management. Below code is executed on 11g and user created successfully, which is expected result.